Shoulder dystocia

Question 1

What is shoulder dystocia?

Answer 1

Refers to a situation where, after delivery of the head, the anterior shoulder of the foetus becomes impacted on the maternal pubic symphysis or (less comonly) the posterior shoulder becomes impacted on the sacral promontory

Question 2

What is the incidence of shoulder dystocia?

Answer 2

0.7% of all deliveries

Question 3

Describe the delivery of the head and shoulders in normal labour

Answer 3

The fetal head is delivered via extension out of the pelvic outlet
This is followed by restitution of the fetal head, so it lies in a neutral position in relation to the spine
The shoulders now lie in an anterior-posterior position

Question 4

What can applying traction of the foetal head cause?

Answer 4

Brachial plexus injury

Question 5

List some risk factors for shoulder dystocia

Answer 5

Pre-labour

• previous shoulder dystocia (X10)
• Macrosomia
• DM
• Maternal BMI >30
• Induction of labour

Intrapartum

• Prolonged 1st stage of labour
• Secondary arrest
• Prolonged second stage of labour
• Augmentation of labour with oxytocin
• Assisted vaginal delivery - forceps or ventouse

Question 6

What is shoulder dystocia defined by?

Answer 6

Delay in delivery of the shoulders following the head during vaginal delivery with the next contraction after using normal traction

Question 7

What signs on examination indicate shoulder dystocia?

Answer 7

Difficulty in delivery of the fetal head or chin

Failure of restitution - foetus remains in the occipital-anterior position after delivery by extension and therefore does not turn to look to the side

Turtle neck sign - the foetal head retracts slightly back into the pelvis, so that the neck is no longer visible, akin to a turtle retreated into its shell

Question 8

Describe the management of shoulder dystocia

Answer 8

Call for help - obstetric and neonatal emergency 2222

Advise mother to stop pushing

Avoid downward traction of the foetal head

Consider episiotomy to make manoeuvres easier

McRoberts manoeuvre - hyperflex maternal hips (knees to chest position) - widens the pelvic outlet

Suprapubic pressure is either a sustained or rocking fashion to apply pressure behind the anterior shoulder to disimpact it from underneath the maternal symphysis

2nd line manoeuvres

• Posterior arm - insert hand posteriorly into sacral hollow and grasp posterior arm to deliver
• Internal rotation (corkscrew manoeuvre) - apply pressure simultaneously in front of one shoulder and behind the other to move baby 180 degrees into oblique position

If manoeuvres fail, roll patient onto all fours and repeat

Cleidotomy - fracturing the clavicle
Symphysiotomy - cutting the pubic symphysis
Zavenelli - returning the foetal head into the pelvis for delivery of the baby via caesarean

Question 9

Describe the post delivery management of shoulder dystocia

Answer 9

Active management of the 3rd stage of labour - increased risk of PPH

PR examination to exclude 3rd degree tear

Debrief the mother and birth partner and advise them of the risk of recurrence with any subsequent delivery

Consider physiotherapist review before discharge as women are at increased risk of pelvic floor weakness/3rd degree tear, MSK pain and temporary nerve damage

Paediatric review to assess for brachial plexus injury, humeral fracture or hypoxic brain injury

Question 10

List the complications of shoulder dystocia

Answer 10

Maternal - 3rd or 4th degree tears (3-4%), PPH

Foetal - Humerus or clavicle fracture, brachial plexus injury, hypoxic brain injury